About 20 years after the publication of the first guidelines on environmentally friendly procurement, a critical interim assessment of their successes is being made. Extensive analyses of procurement practices, market reactions, and areas for improvement form the basis of the study. A comprehensive presentation of the permissible environmental requirements in German, European, and international law demonstrates the compatibility of environmental policy and procurement law. Calculations of the achievable potential for environmental relief illustrate that administrations have much more than just a symbolic influence. To counter the often tedious day-to-day implementation of environmentally friendly procurement in administration, the book provides an analytical tool for self-evaluation of the obstacles.